The sliding doors that close autonomously are of great interest, especially in the domestic and commercial areas, for energy efficiency reasons. The use thereof in any type of air-conditioned enclosure or space enables, for example, to significantly reduce the energy consumption intended for the thermal adaptation thereof.
Nowadays, there are known different types of devices, more or less complex, which enable to perform the autonomous closing of sliding doors in a more or less efficient manner.
Among the most simple ones, we can highlight the devices using one or more coil springs arranged longitudinally in the direction of the upper profile, where one of the ends is extended pushed by a drag mechanism integral to the sliding leaf during the opening thereof. Once the sliding leaf is released, it is pushed in the closing direction by the spring, which tends to recover its resting state. Generally, these devices are combined with the use of a cylinder-piston that serves to damp the closing. This type of devices has several problems. The first one of them is that, once the spring is selected and the device is installed there is no possibility of adjusting the closing speed. The second problem is that the closing does not occur at constant speed, that is, the sliding leaf is initially accelerated and then slows down producing sudden movements which can produce clashes, dangerous situations and swinging movements which can produce vibrations. The third problem is that, with time the spring starts to lose elastic strength until being insufficient to produce the complete closing of the door.
Among the most complex closing devices we can highlight those that use a cable featuring an end joined to the sliding leaf, while the other end is related to a spring. The operation mode related to the door closing is equivalent to the previous case, during the opening of the sliding leaf the cable is extended tightening the spring, and once the sliding leaf is released the spring is loosen and pulls from the cable to drag it. The operation mode related to the stop of the sliding leaf does have considerable differences compared to the previous case. More specifically, this type of devices requires the use of external stops which are arranged on some fixed point of the door. Among the different possibilities there are highlighted the use of elements that act as stops or rack-sections arranged near the side where the door is closed. In the case of racks, they are generally configured to receive a toothed pulley arranged on the sliding leaf. Once the toothed pulley is engaged with the rack the movement of the sliding leaf slows down. This type of devices has problems similar to the preceding case. That is, there is no possibility of adjusting the closing speed, said closing does not occur at constant speed and also sudden acceleration and deceleration events occur that can deteriorate or break elements of the device or the door, or even cause accidents. Besides these problems, there are mounting difficulties produced by the fact that there is an external stop to attain a correct adjustment.
In order to solve the aforementioned problems, the self-closing device for sliding doors of the present invention has an efficient and secure design that allows the closing of the sliding leaf at an adjusted constant speed at the users will, while having a reduced and compact size which facilitates mounting and maintenance tasks.